Synthesis
GENERAL STEPS: In a typical experiment, 2-methylphenylboronic acid (1.22 g, 10 mmol) was added to a flask containing K2CO3 (2.76 g, 20 mmol) and water (2 mL) as solvent. Aniline (0.93 g, 10 mmol) and Cu-Mn catalyst were subsequently added and the reaction mixture was stirred at room temperature. The reaction process was monitored by thin layer chromatography (TLC). After completion of the reaction, the base in the reaction mixture was neutralized with 2N HCl solution and the catalyst was removed by filtration. The filtrate was washed thoroughly with water and then extracted with ethyl acetate. The organic layer was separated and concentrated and dried under reduced pressure. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/petroleum ether, ratio 1:5) to give white crystalline 2-methyldiphenylamine (1.60 g, 95% yield). All reactions were carried out in a similar manner.
References
[1] Tetrahedron Letters, 2013, vol. 54, # 39, p. 5351 - 5354
[2] RSC Advances, 2014, vol. 4, # 90, p. 49273 - 49279
[3] Bulletin of the Korean Chemical Society, 2012, vol. 33, # 5, p. 1785 - 1787
[4] Journal of Organic Chemistry, 2006, vol. 71, # 25, p. 9522 - 9524
[5] Tetrahedron Letters, 2014, vol. 55, # 17, p. 2813 - 2817
